There are several techniques for placing an image on a mug or a cup having a handle. One of the techniques used to produce an image on the mug or cup is to use screen printing. Conventional screen printing is accomplished by having a wooden frame wherein a pair of wooden slats are spaced apart such that each lower edge is parallel to the other and the slats angle away from each other as they project upward. The mesh is secured by gluing to the lower and outer edges of the slats. The other two sides of the mesh are secured to the wooden frame. The tension on the screen is minimal, typically one to seven newtons per centimeter. The frame is sized so that the handle of the mug goes from the outer edge of one slat to the outer edge of the other slat as the mug rotates to receive the image. The image is transferred to the mug by a squeegee exerting pressure on the screen, pressing ink through the screen. In conventional screens, the screen engages the mug and the image transfers. The screen separates from the mug after the squeegee passes due to the tension in the screen causing the screen to snap back.
One shortcoming of conventional screens is that because of the low tensions, the squeegee must be moved a sufficient distance past the image on the screen to ensure that the screen snaps back away from the mug or cup. In addition, the deflection of the screen by the squeegee is typically in excess of 1/4 inch because of the low tension on the screen. As indicated above, the screen has to be sized to the mug or cup, and therefore the image is limited in size because the slats are a set distance based on the mug and the image must be spaced sufficiently from the slat to permit the squeegee to pass the image and the screen to snap back.
High tension screens, such as the Newman Roller Mesh.RTM., have rollers for tensioning the screen. The higher tension resulting from use of the rollers results in the screen not deforming as much as conventional screens, therein the squeegee does not have to pass the image by as great a distance for proper snap back thus resulting in a crisper image. However, the rollers engage the handle and prohibit the mug or cup from rotating through a complete rotation as desired and the roller projects inward toward the image portion of the screen from a point where the screen engages the roller therein reducing the space for the squeegee and resulting in a smaller image.
It is desired to have an apparatus and method for printing on a curved surface such as a mug, or cup wherein the screen is held at high tension and allows an image to be printed on a large portion of the mug or cup.